May I ask everyone, if the design pressure of a storage tank is 0.5, what nominal pressure should be used for the equipment flanges?
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May I ask everyone: if the design pressure of a storage tank is 0.5, and the equipment flanges are rated for a pressure of 0.6, but the test pressure is 0.625, can flanges with a nominal pressure of 0.6 still be used? Should we still use a 1.0 device flange?
Check the design temperature and flange material, and determine whether the corresponding maximum allowable operating pressure of the flange is less than the design pressure in order to decide if it can be used. During testing, the flange can generally withstand 1.5 times the nominal pressure
You can check it using my watch: https://bbs.hcbbs.com/thread-2959259-1-1.html
It is recommended to check the standards for equipment flanges on your own; these standards are related to the operating temperature of the medium (the design temperature). For flanges of the same pressure rating, the requirements differ between temperatures of 20 degrees and 300 degrees
To determine the pressure class of a pipe flange, in addition to pressure and temperature, other loads such as pipeline stress and installation stress must also be taken into account; therefore, it is beneficial to choose a slightly higher class. As for the hydrostatic test, due to the short-term load, the pipe flanges can withstand the hydrostatic test pressure at 1.5 times the nominal pressure.
The original poster is confused about the concepts of design pressure and test pressure; read an introductory book on pressure vessels – it’s not possible to explain these things in just a couple of sentences
The allowable pressure in test mode is high! As long as the working condition is ensured, that’s fine! It works!
There is no specification for container flanges regarding \"the hydrostatic test pressure of pipe flanges ≤ Pwmax at normal temperature\".
In the tables on the first few pages of NBT47020, the maximum allowable operating pressure for the flanges of certain devices is higher than their nominal pressure; this is certainly not a problem. In most cases, however, the maximum allowable operating pressure is lower than the hydrostatic test pressure or the design pressure, and cost savings are sought as a result. It seems reasonable to carry out calculations for the flanges of such non-standard devices as well
It was checked last time; the flange standards allow its use